Pandas 正則表達式：從列中提取 url 信息

Question

import pandas as pd    

d = {"Device_Type" : ["AXO145","TRU151","ZOD231","YRT326","LWR245"],
 "Stat_Access_Link" : ["<url>https://xcd32112.smart_meter.com</url>",
                       "<url>http://tXh67.dia_meter.com</url>",
                       "<url>https://yT5495.smart_meter.com</url>",
                       "<url>https://ret323_TRu.crown.com</url>",
                       "<url>https://luwr3243.celcius.com</url>"]}

df = pd.DataFrame(data = d)

我有一個這樣的 dataframe，我需要做的是使用正則表達式從標簽中提取 url 信息。 output 必須是這樣的：

設備類型	統計訪問鏈接
AXO145	xcd32112.smart_meter.com
TRU151	tXh67.dia_meter.com
ZOD231	yT5495.smart_meter.com
YRT326	ret323_TRu.crown.com
LWR245	luwr3243.celcius.com

任何幫助表示贊賞。

Answer 1

你真的需要正則表達式嗎？

如果您總是有<url>...</url> ，請使用：

df['Stat_Access_Link'].str[5:-6]

否則，您可以使用：

df['Stat_Access_Link'].str.extract(r'<url>(.*)</url>', expand=False)

# OR

df['Stat_Access_Link'].str.extract(r'<url>([^<>]*)</url>', expand=False)

output：

0    https://xcd32112.smart_meter.com
1          http://tXh67.dia_meter.com
2      https://yT5495.smart_meter.com
3        https://ret323_TRu.crown.com
4        https://luwr3243.celcius.com
Name: Stat_Access_Link, dtype: object

Answer 2

str.extract是你需要的：

d = {"Device_Type" : ["AXO145","TRU151","ZOD231","YRT326","LWR245"],
 "Stat_Access_Link" : ["<url>https://xcd32112.smart_meter.com</url>",
                       "<url>http://tXh67.dia_meter.com</url>",
                       "<url>https://yT5495.smart_meter.com</url>",
                       "<url>https://ret323_TRu.crown.com</url>",
                       "<url>https://luwr3243.celcius.com</url>"]}

df = pd.DataFrame(d)
pattern = re.compile(r"(?<=://)(.*)(?=</url)")
df['Stat_Access_Link'] = df['Stat_Access_Link'].str.extract(pattern, expand=False)
print(df)

Output：

  Device_Type          Stat_Access_Link
0      AXO145  xcd32112.smart_meter.com
1      TRU151       tXh67.dia_meter.com
2      ZOD231    yT5495.smart_meter.com
3      YRT326      ret323_TRu.crown.com
4      LWR245      luwr3243.celcius.com

Answer 3

在我看來，您應該考慮使用 pandas 解決方案pd.DataFrame.str.extract ，因為它內置於 pandas 中。

reg=r'\/\/([\s\S]*)<'
df['matched'] = df['Stat_Access_Link'].str.extract(reg)
print(df)

結果如下：

	設備類型	統計訪問鏈接	匹配的
0	AXO145	https://xcd32112.smart_meter.com	xcd32112.smart_meter.com
1個	TRU151	http://tXh67.dia_meter.com	tXh67.dia_meter.com
2個	ZOD231	https://yT5495.smart_meter.com	yT5495.smart_meter.com
3個	YRT326	https://ret323_TRu.crown.com	ret323_TRu.crown.com
4個	LWR245	https://luwr3243.celcius.com	luwr3243.celcius.com

資源

1. pandas 提取物 — https://pandas.pydata.org/docs/reference/api/pandas.Series.str.extract.html
2. 測試你的正則表達式——https://regex101.com/